Multiple function observation and treatment endoscope and preparation process

ABSTRACT

This preparation process for an observation and treatment endoscope for introduction into the human body through an inner duct of a synthetic material cylindrical tube (2) serving as a catheter extending between an external control and observation head (1) and an internal intervention end (3) and having a certain number of cylindrical longitudinal hollow ducts (17, 22, 23) for receiving the illuminating means (21), the observation means (14) and the treatment means (7) is characterized in that it comprises moulding the tube (2) by placing synthetic material in the pasty state around longitudinal mandrels, whose positions and diameters correspond to the future hollow ducts of the tube and ultrafine optical illuminating fibres, solidifying the synthetic material and then extracting the different mandrels.

DESCRIPTION

The invention relates in general terms to the medical observation andtreatment of the human body with the aid of endoscopes, which areintroduced through a natural or artifical internal duct.

Probes or endoscopes are already known making is possible to carry outobservations and/or certain treatments in given areas of a cavity of thehuman body. Such probes are currently used e.g. in urology andgastroenterology. In their most general present form, the mainly have ina cylindrical plastic or synthetic material tube serving as a catheterand extending between an externally controlled observation headmanipulated by the surgeon and an internal intervention or operationend, a certain number of longitudinal hollow ducts for receivingilluminating means, observation means and treatment means.

The appearance a few years ago of optical fibres has led to significantimprovements to such equpment by permitting the easy illumination andobservation of the working area. In addition, laser probes constitutedby an optical fibre transmitting the radiation of a power laser andwidely used for obtaining, as a function of the wavelength of the laserlight, either a local burning of the undesired body part, or thecrushing of a renal calculus. An endoscopic operating probe of this typeis e.g. described in GB-A-2 167 688, published on Jun. 4th 1986. Thisdocument shows an endoscope having an externally controlled observationhead and an operating end connected to one another by a plastic tubehaving four orifices 3, 7, 8 and 10 and used for the observation,illumination, passage of an operating instrument and circulation of anirrigating liquid for the working area. This probe is completed at itsoperating or intervention end by a balloon 12, which can be inflatedfrom the outer control head and which permits, following theintroduction of the probe into the internal duct of the human body, toensure a relative fixing thereof by gripping along the walls of saidduct.

This document, which summarizes the state of the art prior to thepresent application, also provides an understanding and illustration ofthe disadvantages of such equipment and reference will be briefly madethereto hereinafter.

Firstly, an endoscopic probe according to GB-A-2 167 688 is notfunctionally viable in the state in which it is described in saiddocument for the following reason. When, as is often the case, theoperating instrument introduced through the duct 8 is a fibre suppliedby power laser, e.g. of the YAG type or a dye laser, the distal end ofsaid fibre is significantly heated during its operation. This phenomenonis increased and makes the operating instrument inoperable when organicdeposits agglutinate at the end of the laser fibre, which reachestemperatures from 100° C. (boiling point of the water of the cells) tomore than 1000° C. Unless special precautions are taken, the thusenitted thermal energy may destroy the entire internal operating end ofthe tube and in particular that of the illuminating and observationfibres (the latter being destroyed as from 70° C.) and also the lens bythe thermal shock action.

Moreover, an apparatus according to said document and whose tube isproduced by extrusion means that the latter will have minimum diametervalues of approximately 4 mm, without it being possible to drop belowthis size. This limits the use of such endoscopes, particularly withregards to the examination of small ducts in the human body such asarteries (coronary arteries in cardiology), veins or the introduction ofa probe for crushing renal calculi, whereby in this case the probenecessarily must clear the uterovesical orifice located at the outletfrom the bladder and whose normal opening in the adult is approximately2.3 mm. Therefore, for the treatment of renal calculi using the priorart probes and instruments like that described in the aforementionedBritish document, the surgeon has to bring about a progressive expansionof the opening, which requires a general anasthesia lasting severalhours.

Finally, all the hitherto know endoscopes are monofunctional, i.e. theyare all designed in the case of operating equipment, to operate with asingle given probe, e.g. a laser probe, an ultrasonic probe or grippingtweezers. Thus, if when operating a surgeon successively has to useseveral operating methods, in theory it is necessary for him to changethe endoscope on each occasion, which can not be carried out inpractice.

The object of the present invention is to provide an endoscopicobservation and treatment apparatus making it possible to obviate thedisadvantages referred to hereinbefore by offering equipment which issignificantly miniaturized compared with the known equipment and makingit possible, with the same apparatus, to realize several differentfunctions during an operation, as required by the surgeon.

The present invention therefore relates to a preparation process for anendoscopic observation and treatment apparatus for introduction into thehuman body through an internal duct of a cylindrical synthetic materialtube serving as a catheter extending between an externally controlledobservation head and an internal operating end and having a certainnumber of cylindrical, longitudinal, hollow ducts for receiving theilluminating means, the observation means and the treatment means,characterized in that it consists of moulding the tube by bringing thesynthetic material in the pasty state around longitudinal mandrels,whose positions and diameters correspond to the future hollow ducts ofsaid tube and ultrafine illuminating optical fibres, solidifying thesynthetic material and then extracting the different mandrels.

This process for the preparation of the cylindrical, bicompatiblesynthetic material tube (PVC, Teflon, etc.) serving as a catheter andwhich consists of producing the same by moulding around previouslypositioned mandrels leads to certain of the essential advantages of theinvention. Thus, it firstly and particulary makes it possible to reduceto very small sizes below 0.15 mm and even down to 0.05 mm, thethickness of the walls separating the longitudinal hollow ducts of thetube. This leads to a considerable space saving compared with theplastic material tubes obtained by the method used up to now, namelyextrusion, which does not make it possible to obtain good quality hollowducts separated by walls of size below 0.20 mm. The above figuresimmediately reveal the interest of the production process by mouldingthe tubes from synthetic material, because the significance of theminiaturization of the endoscopic probe for the patient and surgeon andobvious.

Moreover, there are now ultrafine optical fibres with a diameter closeto 50 micrometers, which makes it possible by moulding directly duringproduction a large number of said ultrafine fibres in the free spacesbetween hollow ducts to obtain the same cross-section of transmissionfor the lighting flux with a distribution, whose overall dimensions inthe sense of the diameter of the tube and much smaller, whilst leadingto a better catheter flexibility. This is the second advantage of usingmoulding, because in the case of production by extrusion, it would beimpossible to obtain channels of 50 micrometers and to then introduceinto them one by one the different illuminating optical fibres.

The invention also relates to a multifunction observation and treatmentendoscopic apparatus for introduction into the human body through anatural or artificial internal duct, which mainly comprises acylindrical synthetic material tube serving as a catheter and extendingbetween an externally controlled observation head and an internalintervention or operating end provided with an inflatable fixingballoon, a certain number of cylindrical longitudinal hollow ducts forreceiving illuminating means, observation means and treatment means,characterized in that the tube is obtained by moulding with an externaldiameter below 2 mm and in that the hollow duct are separated from oneanother by walls which, at the location of their minimum thickness, havea size below 0.10 mm and which, if need be, can descend to 0.05 mm, saidtube having illuminating means constituted by a plurality of ultrafineoptical fibres with an individual diameter of approximately 50 μmdistributed and embedded in the synthetic material of the tube duringthe preceding moulding operation, an observation optical fibre, whoseintervention or operation side end is provided with optical accomodationmeans and whereof the observation side end is provided with a screw andrack system permitting the axial displacement of the fibre within thetube, an intervention or operation fibre, which is also regulatable inaxial translation within the tube with the aid of a screw and racksystem fixed to the observation head, an adequate radial clearance beingprovided between the tube and the said fibre to permit the circulationof a cooling liquid along the same and a hollow channel with a diameterclose to 1 mm for the circulation of an irrigation and/or suction liquidand the introduction, as a function of the instantaneous needs of thesurgeon, of a random operating means, particularly and optionally, oneof the operating means chosen from among ultransonic probes,microdrills, biopsy probes, coagulation probes, spark probes, laserprobes and optical fibre pressure measuring probes.

Among the original features of the aforementioned apparatus are thegeneral dimensions of the tube obtained by moulding with an externaldiameter below 2 mm, as well as the illuminating means constituted by aplurality of ultrafine optical fibres embedded in the synthetic materialof the tube during manufacture. These two characteristics have anessential effect on the miniaturization and make it possible tosubstantially divide by two the present diameter of endoscopic probes.

Moreover and still in accordance with the present invention, theobservation optical fibre and the intervention fibre are bothregulatable in translation by means of a screw and rack systempermitting their displacement with respect to the observation head. Thisvery interesting feature of the apparatus according to the inventionmakes it possible to create acceptable working conditions at theinternal intervention or operation end of the catheter for reasons:

(a) The reciprocal displacement in translation of the opticalobservation fibre and the invention fibre makes it possible, byreciprocal axial displacement, to avoid burning the observation fibreand the complete catheter intervention end when, as was mentionedhereinbefore, the intervention fibre is a laser fibre, whose end canreach temperatures of 1200° C.

(b) This structure, which permits the axial displacement of the opticalfibre, permits the movement of the latter alone by a few centimeters infront of the intervention end either to clear an unexpected obstacleoccuring on introducing the catheter, or for carrying out thecalibration of a contraction zone.

According to the invention, the intervention fibre can either be a laserfibre, or an ultrasonic fibre. As a function of the wavelength which istransmitted by them, laser fibres can be used either for buring anundesirable tissue or, particularly in urology or in gastroenterology,for crushing a calculus by thermal shock. The miniaturization achievedwith the aid of the means according to the invention and which leads toa tube with an external diameter below 2 mm makes it possible,particularly in urology, to achieve a very substantial advance becausethe thus obtained instrument clears, without any need for expansion andconsequently general anesthesia, the uterovesical passage making itpossible to reach the kidney after clearing the bladder.

Finally, the presence in the synthetic material tube of a hollow channelwith a diameter close to 1 mm and reserved for the circulation of the asuction and/or irrigation liquid and with a size adequate forsimultaneously permitting the introduction of a random operating meansas a function of the instantaneous needs of the surgeon gives theapparatus its multifuctional character. Thus, according to theinvention, it is possible to use said channel either for a second laserfibre, which in this case would have a different function from the firstintervention fibre, or for an ultrasonic probe, so that the apparatusaccording to the invention makes it possible to use either two laserintervention fibres, or two ultrasonic intervention fibres, or incombination a laser fibre and an ultrasonic fibre, whereby the lattercan also be replaced in situ and during the operation by a microdrill,by a biospy probe, a coagulation probe, a spark probe, etc. In the caseof using a single ultrasonic probe, the latter can be used as a bistouryfor its destruction function. In this case where the apparatus accordingto the invention is used for the simultaneous introduction of twoultrasonic probes, it is e.g. possible to use one as the emitting probeand the other as the receiving probe, which makes it possible to carryout a local echrography and even, when there is a blood flow in a bloodvessel, echography by Doppler effect. Such ultrasonic probes andmicrodrills can be of particular interest in cardiology, where theirintroduction either into coronaries having stenoses, or into cardiaccavities, makes it possible to obtain vital information on (or to treat)the state of the wall of the vessel or inner cavities of the heart.Doppler effect echography can also make it possible to study in situ themovement of the heart valves.

Spark probes can be used for crushing calculi or mineral concretions.Biopsy probes are also clearly of interest. Optical fibre pressuremeasuring probes can be very useful in traumatological neurosurgery,e.g. for directly observing the pressure within an intracranial fossafilled with cerebrospinal fluid. In an operation of this type, theinventive apparatus is directly introduced into the skull with the aidof an orifice made therein. All the above examples illustrate themultifunctional character of the apparatus according to the inventionwhich makes it possible, with the aid of a single endoscope introducedinto a duct of the body, to carry out a sequence of successiveoperations or interventions of different types.

The invention will be better understood through referring to thefollowing exemplified description of the endoscope, which is given in anillustrative and non-limitative manner with reference to FIGS. 1 to 4,wherein show:

FIG. 1 An overall view of the apparatus according to the invention.

FIG. 2 a turned down sectional view of the operating end of theapparatus.

FIG. 3 A section along the tube of FIG. 2, where the respectivedimensions of the different ducts and probes have been respected.

FIG. 4 A sectional view of the external control and observation head ofthe endoscope.

FIG. 1 shows the multifunction treatment and observation endoscopeaccording to the invention and it is possible to see three essentialelements, namely the externally controlled observation head 1, thesynthetic material tube 2 for transmitting light information and for theintroduction of operating instruments, as well as the internalintervention or operation end 3, provided with its inflatable fixingballoon 4.

To the observation head 1 are fixed an ocular device 5 corresponding, aswill be shown hereinafter, with the observation fibre, a screw and rackdevice 6 making it possible to regulate, within the tube 2, the axialtranslation state of said observation fibre.

In the example of FIG. 1, the first intervention fibre is a laser fibre7 regulatable in translation in tube 2 with the aid of the screw andrack device 8. According to the invention, a radial clearance is leftbetween the laser fibre 7 and the duct which it occupies within tube 2,in order to allow the circulation of a cooling fluid which penetratesthe system at 9.

According to the invention, the observation and control head 1 also hasthe pipe 10 for the introduction and reception of the irrigation and/orsuction liquid flow and, in the same hollow internal duct, the channelsfor introducing an ultrasonic probe 11 or a random operating instrument12 chosen from among those referred to hereinbefore. Finally, saidexternal control and observation head 1 also has an orifice 13 intowhich can be introduced the inflating air for balloon 4, when with theendoscopic probe having reached the desired location within the humanbody, the surgeon decides to fix its translation state with respect tothe wall of the introduction duct by inflating balloon 4.

In FIG. 2, which is a turned down section level with the operating end 3of duct 2, it is possible to see the observation fibre 14, the laserfibre 7 and the ultrasonic probe 11 in their respective longitudinalhollow ducts. For reasons of greater clarity in said FIG. 2 therespective dimensions of the different components have not beenrespected. The synthetic material tube 2 is terminated at its innerintervention or operating end 3 by a thermal coating 15 for providingprotection against heating occurring at this point through the laserfibre 7. The end of the observation fibre 14 is also provided with anaccommodation lens 16 connected to said end of the fibre 14, or moresimply constituted by the appropriate size of said fibre end. Accordingto the invention, the hollow duct 17 serving both for the irrigation andintroduction of the ultrasonic probe 11 can also be used for supplyingto the operating point another random treatment means, e.g. in the caseof FIG. 2, a microdrill 18 mounted on the end of a cable 19, which canbe manipulated from the external control head.

Finally, in order to make the apparatus completely opertional, tube 2has in appropriate hollow ducts at least one flexible rigidificationcore 20 for giving the probe a desirable profile during its introductionand its advance in the inner duct of the human body. An inflatableballoon 4 is also provided at the end 3 of tube 2. The balloon isinflatable in per se known manner with the aid of a pressurized air flowintroduced in duct 13. In FIG. 2 the walls of said balloon are shown incontinuous line form in its inoperative position and in mixed line formin its inflated position, where to a certain extent it permits thefixing of the tube in translation along the not shown wall of theinternal duct into which it is introduced.

As has been explained hereinbefore, the translation regulating means 6and 8 of the observation fibre 14 and the laser fibre 7, as well as thethermal coating 15 make it possible, by choosing the translation stateof fibres 7 and 14, to protect against heating by the laser the end 16of the observation fibre 14.

FIG. 3 is a section along tube 2 of FIG. 2 and gives a more precise ideaof the reciprocal dimensions of the three hollow ducts traversing saidtube, as well as the ultrafine optical fibres 21 carrying the light forilluminating the treated area.

In FIG. 3, it is once again possible to see the tube 2 and therigidification cores 20. It is also possible to see the variousultrafine optical fibres 21 embedded in the synthetic material mass oftube 2 in the areas left free by the three ducts 17, 22 and 23. Asexplained in the introduction to the text, an essential feature of theinvention is the process for producing said tube 2 and the ducts 17, 22,23 traversing it, which is carried out by moulding using mandrels whichare subsequently extracted. In accordance with the production processfor said tube 2, the different ultrafine optical fibres 21, whosediameter is close to 50 micrometers, are integrated into the syntheticmaterial mass 2 and embedded in the latter at the time of mouldingsynthetic material 2. Channel 22 for receiving the laser fibre 7 has adiameter of approximately 0.3 mm, as has the channel 23 for receivingthe observation fibre 14. However, an annular space is provided betweenthe laser fibre 7 and the channel 22 for permitting the circulation ofthe cooling fluid injected by orifice 9, cf. FIG. 1. Channel 17 for theintroduction of ultrasonic probe 11 and microdrill 18 has a diameter ofapproximately 1 mm which is adequate to at the same time permit thecirculation of the irrigation liquid for the working area. The externaldimensions of the tube 2 of FIG. 3 are, in the present embodiment, adiameter of 2 mm.

The intensity of the illuminating light flux carried by the differentultrafine fibres 21 is directly dependent on the surface of thecross-sections of these different fibres and through having distributedlarge numbers thereof by embedding them in the synthetic material massof the tube 2 makes it possible to obtain an equal lighting for reducedoverall dimensions consisting of that of a single circular fibre with asurface equal to the sum of the elementary surfaces of the fibres 21.Moreover, the distribution of these illuminating fibres 21 in a largenumber of ultrafine fibres leads to greater strength and bendingresistance on the part of the illuminating device compared with thesolution having a single fibre.

FIG. 4 shows in section the external control and observation head 1 andits junction with the synthetic material tube 2. It is possible to seethe various elements already described with their relevant referencenumerals, as well as additionally the control motor 24 for themicrodrill 18 using the metal cable 19, the ultrasonic source 25supplying fibre 11 with ultrasonic operating power and the laser 26supplying luminous energy to laser fibre 7. FIG. 4 also shows in greaterdetail the arrangement of the screw and rack system 8 and the system 9for introducing the cooling liquid making it possible to inject acertain quantity thereof between fibre 7 and the hollow ductcorresponding to the interior of the synthetic material tube 2.

What is claimed is:
 1. Multifunction observation and treatmentendoscopic apparatus for introduction into the human body through anatural or artifical internal duct, which comprises:a cylindricalsynthetic material tube serving as a catheter and extending between anexternally controlled observation head and an internal end provided withan inflatable fixing ballon, said tube including a plurality ofcylindrical longitudinal hollow duct for respectively receivingilluminating means, observation means and treatment means, wherein thetube has an external diameter of less than 2 mm and wherein the hollowducts are separated from one another by walls which, at the location oftheir minimum thickness, have a size of less than 0.10 mm, saidilluminating means including a plurality of ultrafine optical fibreswith an individual diameter of approximately 50 μm distributed andembedded in the tube, said observation means including an optical fibre,having an end provided with optical accommodation means and having anobservation side end which includes a screw and rack system forpermitting axial displacement of the fibre within the tube, a fibrewhich is regulatable in axial translation within the tube; a screw andrack system fixed to the observation head for regulating said fibre inaxial translation within the tube wherein a radial clearance is providedbetween the tube and said fibre to permit the circulation of a coolingliquid along the same and a hollow channel with a diameter ofsubstantially 1 mm for the circulation of a liquid and the introduction,as a function of instantaneous needs of the surgeon, of random operatingmeans.
 2. Endoscopic apparatus according to claim 2, wherein the fibrewhich is regulatable comprises a laser radiation transmission fibre. 3.Endoscopic apparatus according to claim 2, wherein the fibre which isregulatable comprises an ultransonic power transmission fibre. 4.Endoscopic apparatus according to claim 2 wherein the end of the tubeincludes thermal protection means.